Organic peroxides and process for preparing the same



United States Patent Efiiidfild- Patented. Dec. 18, 1932 3,069, 17 4 .QEGANIQ AND PRIB CESS PREPARING THE AMlE Alfred Rieehe, Berlin-Wendenschloss, Ernst Schiniiz,

llerlin riiltgiienicire, and Christian lilischolt, Berlin- Baurnschulenweg, Germany, assignors to Deutsche Aitadernie der Wissenschai'ten zu Eerlin, Berlin-Adlershot, Germany No Drawing. Filed Claims priority, a. cation Germany duty 23, 1953 11 (I t 26li-6lt9) The invention relates to the preparation of novel organic peroxides (nionoperoxy acetals).

It has been discovered that acetals derived from aldehydes of the general formula K R2 R1O/ 23, 1959, Ser. No. 803,305

1 mole of alcohol being split off in the reaction, and wherein R is a saturated aliphatic or arylated aliphatic hydrocarbon radical. in this manner, acetals may be quite generally rearranged to new acetals with the abovernentionedalkylhydro-peroxides by gentle heating to 80 C. for several hours, the yield obtained being very satis factory in all instances.

Up to the present it was not known that ace.als could be rearranged to form diiierent acetals by treatment at what might be called mild conditions. The only known reaction similar tothe one described in the specification hereinabove is the exchange of an alkoxy group by an alkyl-peroxide group in the single case of a cyclic ether, viz. isochromane.

The monoperoxide acetals thus obtained are novel cornpounds which have not been described anywhere in the literature. They are surprisingly stable liquids of acetallike odor and comparatively low explosiveness. The lower members or" the group can be vacuum-distilled without decomposition; thus, propiouic-aldehyde-ethyltertiary-butylperoxide-acetal (1-ethoxy-l-tertiary-butylperoxypropane) is easily obtained from propionic aldehyde diethyl acetal and tertiary butylhydroperoxide; it has a boiling point of 4143 C. at a pressure of 24 mm.

The reaction can be formulated as follows:

OCgHs Clia +110 G( ]CHs The 1 ethoxy l tert. butylperoxybutane made from 2 butyric-aldehydediethyl-acetal and tert.-butylhydroperoxide has a boiling point 69-69.8 C. at 16 mm.

These compounds are stable to diluted alkali so that an excess amount of alkylhydroperoxide, which is used in a preferred operating method, may be extracted from the peroxyacetal by means of 2 N NaOH.

As aldehydes all those may be used which are capable of acetalization; as hydroperoxides, the known alkylhydroperoxides such as: methyl-, ethyl-, propyl-, tertiary butyl-, benzyl-, cyclohexene-, tetralin-, decalin-, cumyl-, hydroperoxide, and others. As may be seen from the above, the reaction can be carried out with a large number of compounds.

The novel peroxides are easily manage-able catalysts for starting reactions leading to chain formations, e.g., for the polymerization of vinyl compounds.

In the following, the process of the invention will be described in a number of examples, but it should be understood that these are given by way of illustration and not of limitation and that many changes can be made in the details without departing from the spirit of the invention.

All parts are by weight.

Example 1 Preparation of:

14.6 parts butyric aldehyde diethylacetal are heated with 17.3 parts cumyl hydroperoxide to C. for 7 hours. The reaction mixture is extracted by shaking 5 times with 2 N NaOi-l, washed with Water, dried with N32C03 and concentrated by evaporation at a pressure of 0.02 min. mercury column on a bath having the temperature up to C. for eliminating the split off ethanol. The peroxide is obtained as a non-distillable liquid smelling slightly of acetal, which will deflagrate upon overheating.

Yield: 17.2l pts. (70% of the theoretical yield) n =l.4822.

Example 2 Preparation of:

p-nitrophenyl-methoxy-tert.-butyl-peroxyruethaue of the theoretical yield) n =l.5l57.

speaava Example 3 Preparation of:

*03115 CH3(CH2)5CH CH3 O-OCCsH l-etl1oxy-1-cumylperoxy-heptane 6.6 parts enanthaldehyde diethylacetal are heated With 5.5 parts cumyl hydroperoxide for 6.5 hours to 85 C. (bath temperature). The mass is then shaken 4 times with 2 N NaOl-I, Washed with Water, and concentrated by vacuum distillation at 0.03 mm. mercury column until the bath temperature is 80 C. The peroxide remains as clear oily liquid.

Yield: 7.3 parts (84% n =1.4S16.

of the theoretical yield) l-ethoxy-l-tert.-butylperoxy-heptane 10.9 parts enanthaldehyde diethylacetal are heated with 6.5 parts tertiary butyl hydroperoxide for hours to 80 C. (bath temperature). Then the mass is shaken 4 times with 2 N NaOH, Washed with Water and, after addition with the same volumetric amount of ether, dried with Na CO and fractionated.

Yield of pure compound: 9.2 parts (70% of the theoretical yield), boiling point =46.5 C., 11 1.4208.

Example 6 Preparation of:

/O (32H: 0611 011 CH3 Phenylethoxy-tert.-hutylperoxy-methane 13.6 parts benzaldehyde diethylacetal are heated with 6.75 parts tertiary butyl hydroperoxide for 8 hours to 80 C. (bath temperature). Thereupon, the mass is shaken 4 times with 2 N NaGH, washed with Water, and evaporated in vacuo to a bath temperature of 80 C. A colorless oily liquid is obtained, smelling faintly of acetal. Yield: 12.3 parts (73% of the theoretical yield) n =1.4-814. 7

Example 7 ireparation of:

O-Cg1i5 (IJHs OO"()OITI3 l-ethoxy-l-tert.-butylperoxy-propane 10.7 parts propionic aldehyde die-thylacetal are heated with 7.3 parts tertiary butyl hydroperoxide for 7 hours to 85 C. (bath temperature). The mass is shaken 3 times with 2 N NaOH, Washed with Water, dried With Na C0 and fractionated. Boiling point =67 C.

Yield: 12.8 parts (89% of the theoretical yield) n =1.4029.

What is claimed is:

1. Organic peroxides of the general formula wherein R is a member of the group consisting of nhexyl, phenyl and p-nitrophenyl, R is a member of the group consisting of methyl and ethyl, and R is a member of the group consisting of tert.-butyl and curnyl.

2. 1-ethoxy-l-cumylperoxy-heptane.

3. p-Nitrophenyl-rnethoxy-tert.-butylperoxy-methane.

4. Phenyl-ethoxy-tert.-butylperoxy-methane.

5. 1-ethoxy-1-tert.-butyl-peroxy-heptane.

6. A process for preparing organic peroxides of the general formula OB: H/

wherein R is a radical selected from the group consisting of saturated aliphatic hydrocarbon radicals, aromatic hydrocarbon radicals and nitro-substituted aromatic hydrocaroon radicals, R is a radical selected from the group consisting of saturated aliphatic and arylated aliphatic hydrocarbon radicals, and R is an alkyl radical, which comprises reacting an acetal of the formula wherein R and R are radicals as above defined with a hydroperoxide ROSE for 610 hours at 60 to 80 C. and separating the alcohol formed in the reaction from the peroxide formed by subjecting the reaction mixture to distillation under reduced pressure, thereby recovering the peroxide as a separate phase.

7. A process for preparing l-ethoxy-l-cumylperoxybutane which comprises reacting butyric aldehyde diethyl acetal with curnylhydroperoxide for seven hours at 80 C. and removing the ethanol split 05 during the reaction from the mixture, whereby l-ethoxy-l-curnylperoxybutane is recovered as the residue.

8. A process for preparing p-nitrophenyl-methoxytert.-butylperoxy-methane which comprises reacting pnitrobenzaldehyde-dimethyl acetal With tert.-butylhydroperoxide for 10 hours at 80 C. and removing the methanol split oil during the reaction from the mixture, whereby the p-nitrophenyl-niethoxy-tert.-butylperoxymethane is recovered as the residue.

9. A process for preparing l-ethoxy-1-tert.-butyl-peroxy-butane which comprises reacting butyric aldehyde diethyl acetal with tert.-butylhydroperoxide for 6 hours at 80 C., separating the ethanol split oil during the reaction from the mixture, and then recovering the 1- ethoxy-1-tert.-butyl-peroxy-butane by distillation.

10. A process for preparing 1-ethoxy-1-tert.-butylperoxy-propane which comprises reacting propionic aldehyde diethyl acetal with tert.-butylhydroperoxide for 10 hours at 80 C., separating the ethanol split 05 during the reaction from the mixture, and then recovering the 1-ethoxy-1-tert.-butyl-peroxy-propane by distillation.

11. A process for preparing 1-ethoxy-1-tert.-butylperoxy-heptane which comprises reacting enanthaldehyde 5 E diethyl acetal with tert.-buty1hydroperoxide for 10 hours OTHER REFERENCES at 80 C., separating the ethanol split off during the re- ClOver: jour Amer Chem Vol. 44 (1922), page action from the mixture, and then recovering the 1- 1116 (1page) ethoxy-l-tert.-buty1-peroxy-heptane by distillation. Milas et a1: 1mm Amer Chem Soc VOL 76 (1954) 5 pp. 2322-25 (4 pages). References cued m the file of this patent Milas et 211.: Jour. Amer. Chem. Soc., vol. 77 (1955),

UNITED STATES PATENTS pp. 25362538 (3 pages).

2,776,319 Ropp Jan. 1, 1957 (Copies of above in Patent Office Library) 

1. ORGANIC PEROXIDES OF THE GENERAL FORMULA
 6. A PROCESS FOR PREPARING ORGANIC PEROXIDES OF THE GENERAL FORMULA 